Built Motor - Detonation Fail?

Hi All, first post, looking for some help identifying what's gone wrong here.

08 MS3, I built the motor about 3k miles ago (GF had driven car through a "small puddle" and sucked water through CAI). Anyway, car had been running well enough after the rebuild that I didn't suspect anything was wrong. On a whim I got a cheap borescope to check things out prior to installing new parts / tuning. The pistons are destroyed, see pics, they all look like this. Clearly, I've screwed up. Because it's all 4 I'm thinking timing or fueling but I'm hoping to get some opinions.



Background info on build: This was my first full build so nothing is off the table in terms of stupidity, although I consider myself mechanically competent. Basically all internal components were replaced due to water ingress, I can provide more details if necessary. Running an AP and cobb ots stage 1 tune. Car has a CAI and I did the following during the rebuild: hpfp, injector seals, in-tank fuel pump, bsd, K04 CHRA, rmm, 1 step colder plugs. I have been loosely monitoring fuel pressure, engine temp, BAT, AFR and everything has seemed ok although I didn't take logs. I have not been watching knock retard.

 

Knock is something you should have on your monitors at all times. If you've been doing pulls and not monitoring that you're in for a bad time. You also should not be using a random OTS map for your built motor as anything but a stopgap for a real tune. Generally when you rebuild everything you'd use the MAF curve from an OTS map of the same intake size and that's about it.

That said, I'm not sure what has caused the fuckery on your pistons, but it's not looking nice in there. You do need to get some logs to get an idea of what the hell is going on, but there's a lot of information that could help explain this a bit. If you're just monitoring AFRs at cruising, you're probably trimming really hard and it'll LOOK right, but when you go into open loop during a pull you could be all kinds of fucked up. You need to get some logs and a real tune honestly.

And donate, ya filthy animal.